(CNN) -- Editor's note: Eric W. Sanderson is a senior conservation ecologist at the Wildlife Conservation Society and the author of "Terra Nova: The New World After Oil, Cars, and Suburbs." (Abrams, 2013). The opinions expressed in this commentary are solely those of the author.
If you really want to strike a blow for the environment during Earth Day on Tuesday, do yourself and everybody else a favor and stop driving your car in town. Really -- who needs it?
This is not a message for you if you're a farmer or live in a rural area, where it's 20 miles to the grocery store and 100 miles to the nearest hospital. You can keep your car; it's a safety thing.
But for the rest of you -- those of you living, working and going to school in America's cities and big towns-- it's time to work toward something better. This year's Earth Day theme is green cities, and green cities should have no cars.
What does driving get you anyway?
Expense: Want to give yourself a 17% raise? Stop driving. The average American spends more money on transportation than food each year. They spend twice as much money on transportation as on health care. Gas ain't cheap, nor are tires, tolls, taxes, insurance, car payments, speeding tickets and parking to keep your car.
Traffic: You're late to work, in a foul mood, tired of staring at someone else's bumper. This is the modern American condition in and around cities. And it's getting worse every year. In 1982, the average American spent 16 hours each year stalled in traffic; in 2011 traffic contributed an average of 38 hours of misery per year, costing the nation an estimated $120 billion in lost time and wasted fuel.
Noise: Horns honking. Wheels screeching. The grumble of a river of motorcars pouring down the boulevard. Excessive environmental noise is linked to insomnia, stress and deafness. Can you hear me? An estimated 104 million Americans per year are exposed to harmful clamor, most of it derived from traffic.
No parking: Studies show that on average 30% of the traffic in cities is the result of people just cruising to find parking. What is a car without a place to park? A two-ton albatross around the neck.
Quick death: Cars are killers -- of pedestrians, cyclists and other drivers. In America, the lifetime odds of dying by car are 1 in 112; only cancer, heart and respiratory diseases, and suicide kill more Americans.
Slow death: Cars also contribute to cancer and heart and respiratory diseases by spewing pollution, adding heat to the summer-hot city and preventing exercise. You'd feel better and be more productive if you walked or biked your way to work, at least during the nice weather.
Wasted time: On the whole, cars are a lousy way to get people around. A busy city street can move about 4,400 people in cars in an hour. The same street could move 52,000(!) people by bus, streetcar or subway in the same time and use less energy in the process.
And I haven't even mentioned the global effects of getting cars out of cities, among them: Reducing carbon pollution would slow climate change and habitat destruction.
So how would this work? It would require vision, leadership and collective will. Just imagine how a green city might work without cars.
If folks weren't spending their paychecks on the beast, then they might be more willing to support the construction of frequent, clean, attractive, more extensive and cheaper public transportation, a boon for all, especially the elderly and disabled. People might also ride their bikes, or even walk, to work, once the places formerly used to house cars (that is, parking lots and garages) have been replaced with green housing, parks and open spaces for people.
Streetcars, buses and light rail could move people around above ground. Subways could be retrofitted to transport freight rather than people by night. Smaller deliveries can go by bike or clean-fuel, golf-cart-like vehicles.
How about emergencies? Fire engines, ambulances and other emergency vehicles could still use city streets and would get there all the sooner for having less traffic to wade through.
And what about weekends in the country? No problem. Take the trolley up to a city line garage, claim your car and away you go. Just park it there again when you get back.
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